1. Field of the Invention
The present invention relates to handle controllers and trim sets for operating mortise lock mechanisms in which the handle is allowed to "free-wheel", i.e., rotate without retracting the latching mechanism when the mortise lock mechanism is locked.
2. Description of Related Art
Mortise locksets generally include the mortise lock and inner and outer handle controllers or trim sets which operate the mortise lock. The mortise lock is mortised into the door and usually includes the latching mechanism which secures the door to the door frame when the door is closed, as well as the locking mechanism which prevents the latching mechanism from being retracted when the door is locked.
The handle controllers are generally surface mounted on opposite sides of the door and have handles which operate the latching mechanism. In most current designs, the handle on each handle controller is directly connected to a shaft that extends into the mortise lock. The handle controllers also have some means of operating and controlling the lock mechanism in the mortise lock.
Most commonly, the outer handle controller will have a key-operated cylinder lock having a tail that extends through the back of the handle controller and into the mortise lock through the surface of the door. Turning the key rotates the cylinder lock tail which operates the locking mechanism within the mortise lock to lock it and prevent the handle from being turned.
In mortise lock designs of this type, the cylinder lock (or similar mechanical or electrical lock device) in the outer handle controller will connect (via the cylinder lock tail) to a lock input on the mortise lock. The lock input connects to and operates the locking mechanism within the mortise lock. The shaft extending from the handle connects to a handle input on the mortise lock to retract the latchbolt in the mortise lock when the mortise lock is not locked.
Locking the mortise lock will normally block rotation of the handle input or associated linkages between the handle input and the latching mechanism. Locking will also normally extend the deadbolt. When the mortise lock mechanism is not locked, with the deadbolt retracted, rotation of the handle input will retract the latchbolt and allow the door to be opened.
The handle input and the lock input are normally operable from either face of the mortise lock. This allows the mortise lock to be installed in both left and right hand hinged doors. These inputs are engaged by corresponding shafts or members that extend out of the back of the handle controllers and through openings in the face of the door. The handle input is usually driven by the handle shaft and the lock input by the tail on the lock cylinder. This design also allows the inner handle controller to share the handle input with the outer handle controller so that either handle may operate the door, when it is unlocked.
In addition to the lock input and the handle input, prior art mortise locks of the type described often include a third component, referred to herein as the "lock output", extending through the mortise lock case with ends that may be engaged by corresponding components in the inner and/or outer handle controllers. The lock output component is connected inside the mortise lock to the lock mechanism, ultimately including the lock input and the deadbolt. The lock output moves between a locked indicating position and an unlocked indicating position.
When the lock input is moved between the locked position and the unlocked position, the lock output moves accordingly to indicate the locked or unlocked state of the mortise lock. As described, the operation of the lock input also drives the deadbolt. Although the lock output is driven by the lock input from within the mortise lock, it may also be driven directly from outside the mortise lock. This reverse drives the lock input and operates the deadbolt and locking mechanism in the same way that they are operated by the lock input.
In many designs, the inside handle controller includes a deadbolt throw lever which drives the lock output in this manner to lock and unlock the door from the inner side of the door. From the outer side of the door the outer handle controller locks and unlocks the door by driving the lock input.
As is the case with the lock input and handle input, the lock output component can be engaged from either side to facilitate reversing the lock mechanism. On the inner side of the door, the lock output is an "output" because it indicates the locked or unlocked state of the door (by the throw lever position) when the mortise lock is locked or unlocked from the outside of the door. The lock input also acts as a second lock input when the throw lever is moved to extend or retract the deadbolt. On the outside of the door, the lock output is most often not used, although some lock designs do use it to drive an indicator in the outer handle controller to indicate whether the door is locked or unlocked, or that the locked area is occupied or not occupied.
Although the lock input and lock output are described herein as separate elements, in some designs, they may be the same element and comprise a single piece that may be moved between the locked and unlocked positions by the lock cylinder and the throw lever.
The latching mechanism of this type of mortise lock will include one or more latches that extend between the door and the door frame. The latch may be a single conventional latchbolt or it may be one or more vertical rod latches extending out the top and/or bottom edge of the door. Regardless of the particulars of the latching mechanism, however, it normally includes a central operating point at the handle input to which the externally mounted handle controllers will connect. The handle input retracts the latchbolt and/or latch rods out of latching engagement with the door frame when a handle on the inner or outer handle mechanism is turned to open the unlocked door.
Up to now, in devices of this type the handle on each controller has been connected substantially directly to the latching mechanism, most often through a solid shaft, and the locking function of the mortise lock has been achieved by physically blocking the movement of components inside the mortise lock to which the handle shaft connects. The motion of these components is blocked when the door is locked, and turning a key in the outer handle controller disengages the blocking in the mortise lock via the lock input.
The prior art lock device described above has been a highly successful design when the handle is a conventional door knob. However, the advent of lever handles has placed greater demands on the strength and security of the mortise lock components. The outer handle controller, when provided with a lever handle is referred to as a lever handle controller, and the present invention generally relates to such devices, although it may also be used with conventional doorknob handle controllers.
Doors are much easier to open when the handle is shaped as a lever rather than a conventional round door knob. For this reason, lever handles are preferred in some applications, and they may be required under applicable regulations for certain doors in public buildings to facilitate access by the disabled and the elderly.
However, the lever shape of the door handle allows a large force to be applied to the locking mechanism of the door and to the mounting between the door and the locking mechanism. The greater leverage available from a lever handle may allow a vandal or thief to break the internal components of the door lock by standing or jumping on the lever end of the handle.
To address this problem, in other types of lock mechanisms, the handle and lock mechanism have been designed so that operating the lock will disengage the handle from the lock mechanism. This allows the handle to free-wheel or rotate without operating the lock and prevents the lever handle from being used to overstress the internal components of the lock.
However, free-wheeling designs have not heretofore been feasible in mortise locks because of the separation of the handle and lock cylinder in the outer handle controller from the locking and latching mechanisms inside the mortise lock itself. If the free-wheeling mechanism is incorporated inside the mortised portion, it means that the mortise lock portion must be redesigned. This is expensive, and there is limited room inside the mortise lock to accommodate the free-wheeling mechanism. This approach would also require replacing the expensive mortise lock unit in existing installations to provide free-wheeling functionality.
Alternatively, if the free-wheeling mechanism is incorporated inside the outer lever handle controller, it means that the mortise lock must control the free-wheeling mechanism of the outer handle controller so that the free-wheeling of the outside handle stops when the mortise lock is unlocked from the inside handle controller.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide a handle controller for operating a mortise lock which allows the handle to free-wheel when the door is locked, regardless of whether it is locked from the inside handle controller or the outer handle controller.
It is a further object of the present invention to provide a free-wheeling handle controller that may be used with a prior art mortise lock mechanism to add free-wheeling capability to existing mortise lock installations.
It is another object of the present invention to provide a free-wheeling handle controller in which the connection between the handle and shaft extending to operate the door latch is both rugged and reliable, yet relatively inexpensive, the connection allowing a relatively high level of torque to be transmitted through to the door latch from the handle when the door is unlocked.
Another object of the present invention to provide a free-wheeling handle controller having a lock, such as a cylinder lock or electronic lock, which controls the mortise lock and wherein the controller is controlled by the mortise lock to put the handle controller into free-wheeling operation.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.